Joe’s Weather Blog: Active pattern sets up (SUN-10/8)

Joe’s Weather Blog: Active pattern sets up (SUN-10/8)

Good morning…our Staycation continues for about another 10 days or so…yesterday got a chance to head out on a perfect fall day to Somerset Ridge Winery down in Miami Co towards Louisburg. We passed the Cider Mill that was jammed as usual with folks and made the 1st left beyond that…go down a few miles and the winery is on the left…very “country” with some rather pleasant KS wines. We just sat outside for a couple of hours and listened to music…and enjoyed the sunshine and the fall breezes.

The storm that was responsible for sweeping away the warmer air and the humidity ushered in a cooler air mass. This morning the lows dropped to the 40s to near 50°…so a definite autumn crisp feel to the air out there…but the air is also very dry now and will respond nicely to the sunshine on tap…so a big turn around is expected this afternoon.

Forecast:

Today: Sunny and mild with highs around 80°

Tonight: Clear and cool with lows in the 50s

Monday: Mostly sunny through lunch then clouds moving into the region…mild with highs 75-80°

Tuesday: Rain likely and chilly(!). Highs may only be in the 40s. Blustery would be the word I think.

Discussion:

We’re actually in a rather typical and somewhat active weather pattern in the Plains. There have been quite a few severe storms west of the KC area…some locally heavy rains in N MO…a nice rain for the KC area a couple of days ago…and another system passing through the region Monday night through Tuesday. Here is a look at how much rain has fallen in the region over the last 7 days or so…

That next system will create and area of low pressure south of the KC area that will pass towards the Lake Of The Ozarks. I bring that up because IF this was the dead of winter…and IF the temperatures were 30° colder…you could see how that “type” of system would bring us a nice “winter” event around these parts.

Alas that WON’T be the case on Tuesday but it will generate some cold air that will come in on the back side of the system and create some rather chilly weather for us in the KC area. Temperatures MAY only be in the 40s during the afternoon…or perhaps in the lower 50s depending on how things play out with the rain in the region.

The system that will bring this change is now in the western part of the US…on the water vapor loop you can sort of see it digging into the interior NW part of the country. It will be much more apparent tomorrow as it moves into the Rockies…and creates accumulating snow, perhaps even towards the Denver, CO area.

As a matter of fact Denver, CO is under a Winter Storm Warning for tonight into tomorrow…

So IF you’re travelling there or through there…be alert to road/airport issues.

That storm will then dig into the Plains and come pretty much right towards the I-70 corridor later Monday night into early Tuesday afternoon as it moves through KC.

It’s somewhat easier at this point to see the developing storm by going UP into the atmosphere to around 18,000 feet or so…this next animation is a forecast model showing the storm developing and moving through the Plains region Monday into Tuesday night. The RED areas represent what is called vorticity…or where the air has more tendency to broadly rotate..this enhances lift in the atmosphere and can be connected to precipitation depending on moisture availability and other factors.. The blue areas are subsidence…or the tendency for the air to sink…which is the opposite of “lifting” and cooling the atmosphere.

By the way…look closely…we’re also go into “split” flow. There is the main band of the jet stream moving through the northern US/Canada while the disturbance in question splits off. It’s not really connected to the main jet so as a result AFTER it moves away, there isn’t really any cold air to dump into the Plains behind what it generates on it’s own So the shot of chilly weather on Tuesday into Wednesday morning will be short-lived…we should rapidly warm right back up again afterwards.

So as the system comes our way…rain should develop and there may be some thunderstorms as well. Then as the system chills the saturated atmosphere on Tuesday and chilly rain may result. The ingredients are there for a rather “blah” on Tuesday.

Here is the NAM model forecast and I think you can make out the rain chances…

You can also see what’s left of Nate getting absorbed in the flow across the eastern part of the country. Nate came ashore last night as a Category 1 hurricane. Storm surge was the main issue it appears. I saw this 15 minute time-lapse this morning showing how storm surge can happen very quickly. Nate came in during high tide as well…which wasn’t helpful.